1. Field of the Invention
The present invention relates to image scanning devices, and in particular, to an image scanning device including a scanning carriage.
2. Description of the Related Art
Some scanners, facsimiles, copy machines, and the like use a flat bed scanner (hereinafter referred to as “FBS”) in which a scanning unit of a reduction optical system such as a Charge Coupled Device (CCD) is incorporated in a scanning table as an image scanning unit.
In JP-A-2006-197419, an image scanning device 1 includes a carriage 20. A guide shaft 22 extending along the scanning direction is arranged on one side of a scanning range of the carriage 20. The guide shaft 22 is inserted into a guide hole of a supporting unit 23 arranged at one side portion of the carriage 20 so that the carriage 20 is arranged to be freely slidable along the guide shaft 22. A side unit 24 on the side opposite to the supporting unit 23 of the carriage 20 is mounted on a horizontal frame 25 of a device main body arranged to extend in the scanning direction so as to become a free end. When moving the carriage 20, the carriage 20 can be moved by reciprocating a drive belt 26 in the scanning direction with a drive unit such as a motor attached on the supporting unit 23 side of the carriage 20.
When the guide shaft is used as a mechanism for supporting the carriage as in JP-A-2006-197419, the cost becomes expensive since high accuracy is demanded.